Harden a security CHECK in Font::individualCharacterRanges

Harden a security CHECK in Font::individualCharacterRanges

This patch switches to a check (crash) for an assertion failure in
Font::individualCharacterRanges which is only known to occur on OSX
10.9.5. A comment has been added to explain this further. This has the
side benefit of exposing other cases of this bug on other platforms that
may be a more serious issue.

BUG=620952
Committed: https://crrev.com/e4ff7ba1cfab002517238841505ca9bb7aff6595
Cr-Commit-Position: refs/heads/master@{#402912}

[pdr., 2016-06-28 22:31:47]

pdr@chromium.org changed reviewers:
+ fs@opera.com

[fs, 2016-06-29 08:03:05]

lgtm

[pdr., 2016-06-29 17:05:15]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2016-06-29 17:05:41]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-06-29 19:56:04]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-29 19:56:54]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-06-29 19:57:21]

Description was changed from

==========
Harden a security CHECK in Font::individualCharacterRanges

This patch switches to a check (crash) for an assertion failure in
Font::individualCharacterRanges which is only known to occur on OSX
10.9.5. A comment has been added to explain this further. This has the
side benefit of exposing other cases of this bug on other platforms that
may be a more serious issue.

BUG=620952
==========

to

==========
Harden a security CHECK in Font::individualCharacterRanges

This patch switches to a check (crash) for an assertion failure in
Font::individualCharacterRanges which is only known to occur on OSX
10.9.5. A comment has been added to explain this further. This has the
side benefit of exposing other cases of this bug on other platforms that
may be a more serious issue.

BUG=620952

Committed: https://crrev.com/e4ff7ba1cfab002517238841505ca9bb7aff6595
Cr-Commit-Position: refs/heads/master@{#402912}
==========

[commit-bot: I haz the power, 2016-06-29 19:57:23]

Patchset 1 (id:??) landed as
https://crrev.com/e4ff7ba1cfab002517238841505ca9bb7aff6595
Cr-Commit-Position: refs/heads/master@{#402912}